Knauthe, H. E. (1966). Prospective Planning and Investment Decisions: Economic Problems Concerned with Preparation and Carrying out of Investments. The institute of national planning.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Knauthe, Habil Erhart. Prospective Planning and Investment Decisions: Economic Problems Concerned with Preparation and Carrying Out of Investments. Cairo: The institute of national planning, 1966.
توثيق جمعية اللغة المعاصرة MLA (الإصدار التاسع)Knauthe, Habil Erhart. Prospective Planning and Investment Decisions: Economic Problems Concerned with Preparation and Carrying Out of Investments. The institute of national planning, 1966.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.